As a personal watercraft for planing on the waters of the sea and lakes, there is known, for example, a personal watercraft (see, for example, Japanese Patent Laid-open No. Hei 9-281132, FIG. 1). The personal watercraft includes an engine and a jet propeller driven by the engine which are disposed in a hull, and a steering nozzle provided at the rear end of the jet propeller. According to the personal watercraft, the jet propeller is driven by the engine, whereby an impeller of a water jet propeller is rotated, and water is sucked in through an intake port by the rotation of the impeller.
The water thus sucked in is ejected as jet water rearwards from the rear end of the steering nozzle, whereby the personal watercraft can be made to plane by the jet force of the jet water.
For steering the hull to the left and right directions during planing, the personal watercraft has a structure in which the steering nozzle can be swung in the left-right directions. Further, there is a personal watercraft in which the steering nozzle can be swung vertically for maintaining the hull in a favorable planing posture.
For ensuring that the steering nozzle can thus be swung in the left-right and vertical directions, an annular ring is disposed so as to cover the rear end of a jet propeller, left and right side portions of the ring are rotatably connected to the rear end of the jet propeller through left and right support shafts, a front end portion of the steering nozzle is disposed so as to cover the ring, and upper and lower end portions of the steering nozzle are rotatably connected to the ring through upper and lower support shafts.
Here, as the left and right support shafts and the upper and lower support shafts, bolts are generally used. These bolts are assembled in position, with their heads on the outside. Namely, the left and right bolts are inserted into left and right openings from the outside of the ring, and the bolts thus inserted are screw-engaged into threaded holes in the jet propeller, whereby the ring can be vertically swingably mounted onto the jet propeller.
Furthermore, the upper and lower bolts are inserted into upper and lower openings from the outside of the steering nozzle, and are inserted into upper and lower openings of the ring, whereby the upper and lower bolt tips are projected from the upper and lower openings of the ring, and nuts are screw-engaged with the upper and lower bolt tips thus projected, whereby the steering nozzle can be mounted onto the ring so as to be swingable in the left-right directions.
By this, the steering nozzle can be so mounted as to be swingable in the left-right and vertical directions relative to the jet propeller.
However, the nut screw-engaged with the tip end of the lower bolt might become slackened and disengaged from the lower bolt, for example when the personal watercraft is used for a long time. Thus, with the nut slackened, the lower bolt might be disengaged from the steering nozzle.
Therefore, it has been desired to put to practical use a steering nozzle mount structure in which the lower bolt would not become disengaged from the steering nozzle even if the nut should be slackened.
On the other hand, for swinging the steering nozzle vertically, an operating cable is generally connected to an upper portion of the steering nozzle through a joint. At the time of connecting the operating cable to the steering nozzle through the joint, first, the protrusion amount of the joint relative to the operating cable is adjusted to be appropriate.
Second, a mount hole of the joint is fitted over a mount bolt of the steering nozzle, and a nut is screw-engaged with the tip end of the mount bolt projected from the joint, whereby the operating cable is connected to the mount bolt.
After the operating cable is connected to the mount bolt, it is checked to determine whether or not the steering nozzle is mounted at a normal angle.
When the steering nozzle is not directed in the normal direction, the nut is disengaged from the mount bolt, and the steering nozzle is disengaged from the joint.
Subsequently, the joint disengaged from the steering nozzle is rotated relative to the operating cable, whereby the protrusion amount of the joint relative to the operating cable is again adjusted.
After the readjustment is over, a through-hole in the joint is again fitted over the mount bolt, and the nut is screw-engaged with the tip end of the mount bolt projected from the joint, whereby the operating cable is again connected to the mount bolt.
In this condition, it is again checked whether or not the steering nozzle is mounted at the normal angle. When the steering nozzle is mounted at the normal angle, the operation of connecting the operating cable to the steering nozzle is finished.
Thus, for readjusting the angle of the steering nozzle to a normal condition, the nut once screw-engaged with the mount bolt must be disengaged from the mount bolt. Therefore, it takes additional labor to adjust the direction of the steering nozzle to the normal angle.
Accordingly, it is an object of the present invention to provide a personal watercraft in which bolts can be so assembled as not to be disengaged from the steering nozzle even if nuts should be slackened and in which the direction of the steering nozzle can be adjusted to the normal angle without much labor at the time of assembly.